Popular

July 21, 2008

Report: Sea Level Rise Poses Greater Storm Threat

by Sam Savage

By E.B. FURGURSON III Staff Writer

Sea level rise related to global warming likely will inundate land, alter wetlands and devastate wildlife around the Chesapeake Bay region by the end of the century, according to a recent report by the National Wildlife Federation.

By the year 2100, a projected 2-foot rise would make the Pasadena peninsula extremely vulnerable to a damaging storm surger, said Patty Glick, National Wildlife Federation senior global warming specialist and lead author of the report.

"Tropical Storm Isabel was a wake-up call to the area, and it doesn't take much rise in the sea level to make the storm surge much worse," Ms. Glick said. "How many more feet of storm surge we could have really depends on the locality."

Twenty-five miles to the south, Shady Side would see the worst impact in Anne Arundel County, with much of the peninsula reverting to swamp because of a rising water table.

Part of the problem, Ms. Glick said, is that waterfront neighborhoods of Pasadena, including Gibson Island, have been densely developed, destroying natural barriers to storm surge such as marshes.

The federation studied the impacts of sea level rise on the region's coastal habitats and ecosystem. Those changes are likely to adversely affect species that depend on the most threatened habitats, like grasses that shelter young fish and crabs.

"We face the prospect of losing much of what we treasure about the bay - its beaches, wildlife and prized fishing - unless we prepare for the sea-level rise that our new modeling shows will happen," Ms. Glick said. "This analysis goes well beyond simple inundation modeling. It documents for the first time the many landscape and habitat changes that will occur along the entire bay coastline if global warming continues unchecked."

The report released in late May was gleaned from a series of computer-aided studies, each creating data based on various sea- level rise scenarios ranging from a conservative 12.2-inch rise all the way up to a 6.5-foot deluge.

Most of the study's report rested on results from a 27.2-inch rise recognized by the Nobel Prize-winning Intergovernmental Panel on Climate Change.

The data generated by the computer models in the study show an increase of nearly 1,000 acres of swamp in the Annapolis area should sea levels rise by about 2 feet by the end of the century.

The lower end of the bay and Eastern Shore suffer the brunt of habitat changes. Huge areas of the Blackwater Wildlife Preserve could be largely under water. Iconic Smith and Tangier islands would disappear. More than 80 percent of the estuarine and ocean beaches on Virginia's Eastern Shore could be converted to open water.

The ocean beaches that hundreds of thousands of people flock to holiday weekends could nearly disappear.

"The projected changes in the extent and compositionof the region's tidal marshes, in particular, could have far-reaching on the Chesapeake Bay food web," the report said.

Half of the bay's brackish marsh, the dominant form of marsh in the region that not only provides habitat for numerous wildlife species but also helps filter the worst pollutants, could disappear in 50 years.

"The model projected we are in danger of losing 90 percent of the fresh water marsh by 2100," said Dr. J. Emmett Duffy of the Virginia Institute of Marine Science.

He said plants and animals whose life cycle is tied closely to temperatures are already feeling the changes.

"Global warming has already influenced the bay's ecosystem," he said. "Springtime is starting three weeks earlier than it did in 1960, and the summers are hotter." Eel grass is one of those key species. Huge meadows of the critical fish and crab nursery habitat in the southern end of the bay are vulnerable.

"In 2005 high temperatures wiped out the eel grass in a matter of weeks," he said. He suggested that die-off could be a major factor in the swift crab decline in the past couple of years. "Those grasses are already stressed from poor water quality (and) sea level rise would provide a one-two punch to knock it out."

"When we lose habitat for juvenile fish today, there are no fish tomorrow," he said. "We have to look at the way we manage fisheries; it has to take climate change into consideration." The study also prescribed solutions.

"We've spent years working to save the bay, but unless we address global warming, it could all be lost," said Larry Schweiger, president and CEO, National Wildlife Federation. "No single silver bullet will save the bay from the effects of global warming. We need action at all levels of government."

Cutting global warming pollution 2 percent per year to meet an 80 percent reduction goal by mid-century will be necessary to avoid the most damaging effects of climate change, according to leading scientists.

Legislation that cuts global warming pollution is vital in the long range. In the near term, enforcement of current laws checking development and protecting shorelines is crucial.

Marshes and beaches can adjust to rising waters by creeping inland, if they have someplace to go.

But hardening of shorelines with unnecessary rock abutments or bulkheads and building shoreline homes and condos restricts that adaptability, study representatives said.

Governments are moving in the right direction, said Beth McGee, the senior water quality specialist for the Chesapeake Bay Foundation. "The last legislative session in Maryland, there were several bills on energy efficiency," she said.

Maryland has established a statewide Sea-level Rise Response Strategy, and Virginia has put together a Governor's Commission on Climate Change to study sea-level rise impacts on coastal areas and proposed strategies to deal with the inevitable event. {Corrections:} {Status:}